System and method for processing engine roughness for cold start fuel control via electric motor

Patent metadata

Field	Value
Publication number	US-9321450-B2
Application number	US-201414192196-A
Country	US
Kind code	B2
Filing date	Feb 27, 2014
Priority date	Feb 27, 2014
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A system and method for controlling an engine in a hybrid vehicle based on the use of a calculated combustion stability value to modify a pulsewidth signal to fuel injectors of the engine to reduce hydrocarbon emissions, especially following an engine start. The calculated combustion stability value is determined as a function of a torque signal obtained from an electric motor of the hybrid vehicle.

First claim

The invention claimed is:

1. A system for controlling fuel injection in a hybrid vehicle, the system comprising:
an internal combustion engine having at least one fuel injector;
first and second electric motors each having a rotor and a stator, the rotors mechanically connected to the internal combustion engine;
an engine controller connected to the at least one fuel injector; and
first and second motor controllers connected to the first and second electric motors and the engine controller;
wherein the engine controller controls the amount of fuel supplied to the fuel injector of the internal combustion engine based on a calculated combustion stability value determined as a function of motor torque signals obtained from the first and second electric motors via the first and second motor controllers.

2. The system according to claim 1 , further comprising:
resolvers connected to the electric motors and motor controllers; and
current sensors connected to the electric motors and motor controllers;
wherein the motor controllers use feedback from the current sensors and resolvers to measure and control the electric motors.

3. The system according to claim 1 , wherein the motor controllers and the engine controller each include a microcontroller with a digital filter, a memory, and signal conditioning circuitry to process outputs for sensors within the vehicle.

4. The system according to claim 1 , wherein the calculated combustion stability value is based on a difference between successive rate estimate values of the electric motors determined by associating a first motor torque value provided from one of the motor controllers with a position of a cylinder within the combustion engine, and comparing said first motor torque value with a second motor torque value associated with said cylinder one revolution earlier.

5. The system according to claim 1 , wherein the calculated combustion stability value is based on a difference between successive rate estimate values of the electric motors determined by associating a first motor torque value provided from one of the motor controllers with a position of a cylinder within the combustion engine, and comparing said first motor torque value with a second motor torque value associated with said cylinder at least two revolutions earlier.

6. The system of claim 1 , wherein the fuel supplied to the internal combustion engine is controlled by a fuel injection pulsewidth signal sent from the engine controller to the at least one fuel injector; where the fuel injection pulsewidth signal is modified by comparing an average combustion metric value with a desired combustion metric value.

7. The system of claim 6 , wherein the desired combustion metric value is calculated as a function of engine speed, engine load, ambient pressure, time, and coolant temperature.

8. The system of claim 1 wherein the motor torque signals are normalized based on an angle of motor torque readings of the electrical motors.

9. A method for controlling fuel injection in a hybrid vehicle, the method comprising:
determining a combustion stability value for an internal combustion engine as a function of motor torque signals obtained from two electric motors within the hybrid vehicle; and
modifying the amount of fuel supplied to a fuel injector of the internal combustion engine based on the combustion stability value.

10. The method of claim 9 , wherein the calculated combustion stability value is based on a difference between successive rate estimate values of the electric motors determined by associating a first motor torque value provided from a motor controller with a position of a cylinder within the combustion engine, and comparing said first motor torque value with a second motor torque value associated with said cylinder one revolution earlier.

11. The method of claim 9 , wherein the calculated combustion stability value is based on a difference between successive rate estimate values of the electric motors determined by associating a first motor torque value provided from a motor controller with a position of a cylinder within the combustion engine, and comparing said first motor torque value with a second motor torque value associated with said cylinder at least two revolutions earlier.

12. The method of claim 9 , wherein the fuel supplied to the internal combustion engine is controlled by a fuel injection pulsewidth signal sent from an engine controller to at least one fuel injector; where the fuel injection pulsewidth signal is modified by comparing an average combustion metric value with a desired combustion metric value.

13. The method of claim 12 , wherein the desired combustion metric value is calculated as a function of engine speed, engine load, ambient pressure, time, and coolant temperature.

14. The method of claim 9 , wherein the motor torque signals are normalized based on an angle of motor torque readings of the electric motors.

Assignees

• Degroot Kenneth P
• Velnati Sashidhar
• Coatesworth Timothy A
• Zhang Mengyang
• Reynolds Scott A
• Fca Us Llc

Inventors

• Degroot Kenneth P
• Velnati Sashidhar
• Coatesworth Timothy A
• Zhang Mengyang
• Reynolds Scott A

Classifications

• Y02T10/6286

  Cross-Sectional Technologies · mapped topic

• B60W2710/0627

  Fuel flow rate · CPC title

• B60K2006/4825

  Electric machine connected or connectable to gearbox input shaft · CPC title

• F02D41/1498

  measuring engine roughness · CPC title

• B60W10/08

  including control of electric propulsion units, e.g. motors or generators · CPC title